Expansion joint



"April 19 1927. P. MCDONALD EXPANSION JOINT Filed May 17. 1924 GU 0: new

Patented Apr. 19,

UNITED sTA'TEs JOHN 1. IODON'ALD, 01' LUS'IDL mm 810K 30mm.

Application ma ma 17, 1924. serial ll'o. 714,088.

For the sake of illustration, it might be stated that in pavement and road construction it is customary to provide expansion joints between adjacent sections of the pavement or road construction to allow for expansion and contraction of the section, due to heat and cold.

It has been found in practice that the usual expansion joint does not properly. allow the paving to expand, due to the fact that the asphalt filler now in use is a non-conductor and does not heat through the depth of the paving and soften the lower portion of the expansion joint as readily as it should, due to the fact that the concrete is such a conductor of heat and cold that it will heat through and expand before the bottom portion of the present asphalt filler of the expansion joint thereby losing the desired effect of allowing pavement to expand promptly with the heat.

It is therefore the object of the invention to provide an expansion joint of a construction that will overcome this objection by providing a soft filler that will not become hardened b either heat or cold but will retain a smal portion of asphalt filler near the surface of the paving so that the same ma be heated as rapidly as. the paving itsel and allow it to expand as freely as possible.

With the foregoing and other objects in.

view which will appear as the description roceeds, the invention resides in the comination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodimentof the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the invention.

Referring to the drawing:

Figure 1 is a sectional view-through adjacent sections of a road surface disclosing an expansion joint constructed in accordance with the invention.

Figure 2 is a fragmental plan view thereof. Referring to the drawing in detail, the reference character 5 designates adjacent pavement or road sections which are separated by means of an expansion joint indicated at 6, which expansion joint permits of slight movement between the sections caused by expansion and contraction of the sections due to heat and cold.

The expansion joint forming the essence of the invention comprising a lower layer or a lower filling of soft material such as sawdust, ground cork, shavings or the like which will notharden or lose its natural softness through heat or cold, but will at the same time fill the lower portions of said expansion joint in such a manner as to retain a topping of asphalt which will completely fill the joint leaving the two sections of pavement spaced with relation to each other.

The remaining portion of the space between the adjacent ends of the sections is filled with hot asphalt or other bituminous paving filler which will properly seal the joint and exclude water or other foreign matter which would act to deteriorate the joint.

From the foregoing it will be obvious that when the surface of the pavement or roadway of which the expansion joint becomes a part, expands or contracts due to heat or cold, the movement of the sections will be uniform throughout their entire thicknesses, owing to the fact that the lower portion of the joint is free to allow such movement between the sections, the lower portions of the sections receiving no resistance from the lower portion of the joint or filling material employed in forming the joint.

I claim A method of constructing expansion joints for concrete road sections consisting in placing a sawdust filler between the adjacent ends of sections, and at the bottom of the space between the sections, leaving a space the upper surface of the sawdust filler and upper surface of the road sections, and finally filling in bituminous material until the bituminous material engages the sawdust and the upper ed e of the bituminous material is level with t 1e upper surfaces of the road sections. y

In testimony that I claim the foregoing as my own, I have hereto atfixed my signature. v

JOHN P. McDONAIiD. 

